Digital images in reality are usually affected by an imaging device or noise interference from an external environment during digitalization and transmission. In order to acquire information that is more precise from an image, it is necessary to perform denoising processing on the image. A process of reducing noise in a digital image is referred to as image denoising, and the image denoising is a fundamental and key technology in the field of image processing technologies.
In an existing method for implementing image denoising, multiple filtering algorithms may be used to reduce noise of an image. For example, the Gaussian filter is a process of performing weighted averaging on a whole image, and a value of each pixel is obtained by performing weighted averaging on the pixel itself and values of other pixels in a neighboring region, thereby completing the image denoising. However, in the prior art, noise of the whole image is reduced by using a same filter method, and in the case of high noise, if denoising is performed with great strength, the boundary of the image is blurred and loses image details, and if denoising is performed with weak strength, it is possible that noise cannot be removed completely.